List of top Physics Questions

Blowing air with open mouth is an example of

Block $A$ of weight $100\, N$ rests on a frictionless inclined plane of slope angle $30^?$ as shown in the figure. A flexible cord attached to $A$ passes over a frictionless pulley and is connected to block $B$ of weight $W$. Find the weight $W$ for which the system is in equilibrium.

Bernoulli's theorem is applicable in the case of

Bells are made of metal and not of wood because

Beat phenomenon is physically meaningful only, if

Beats are produced by the superposition of two waves of nearly equal frequencies. Of the following, the correct statement is

Beats are the result of

barometer reads 75 cm of mercury. When $2.0 \,cm^3$ of air at atmospheric pressure is introduced into the space above the mercury level, the volume of this space becomes $50 \,cm^3$. The length by which the mercury column descends is

Band spectrum is produced by

Average acceleration vector for a particle having uniform circular motion is

Atomic mass number of an element is 232 and its atomic number is 90. The end products of this radioactive element is an isotope of lead (Atomic mass 208 and atomic number 82). The number of $\alpha\,and\,\beta$-particle emitted is

Atomic weight of Boron is 10.81 and it has two isotopes $_5B^{10}$ and $ _5B^{11}$ Then the ratio of $_5B^{10} :_5B^{11}$ in nature would be

At what temperature will the speed of sound in air be $3$ times its value at $0\,^?C$?

At what temperature is the rms velocity of hydrogen molecule equal to that of an oxygen molecule at $47\,^{\circ}C$?

At zero degree kelvin a piece of Germanium

At what temperature, hydrogen molecules will escape from the earth's surface? (Take mass of hydrogen molecule $=0.34\times10^{-26} kg,$ Boltzmann constant $-1.38\times10^{-23} J K^{-1},$ Radius of earth $=6.4\times10^{6} m$ and acceleration due to gravity $=9.8 ms^{-2}$ )

At what height above the surface of earth the value of acceleration due to gravity would be half of its value on the surface of earth? (Radius of the earth is 6400 km)

At the maximum height of a projectile, the velocity and acceleration are

At the maximum height of a body thrown vertically up

At room temperature, the rms speed of the molecules of a certain diatomic gas is found to be $1933\, m \,s^{-1}$. The gas is $(R = 8.3\, J\, mol^{-1}\, K^{-1}$ )

At resonance frequency the impedance in series $LCR$ circuit is

At constant temperature, the volume of a gas is to be decreased by 4%. The pressure must be increased by

At any instant, a rolling body may be considered to be in pure rotation about an axis through the point of contact. This axis is translating forward with speed

At any instant the ratio of the amount of radioactive substance is 2 : 1. If their half lives be respectively 12 and 16 hours, then after two days, the ratio of the substances is

At a given instant, there are $25\%$ undecayed radioactive nuclei in a sample. After $10$ seconds the number of undecayed nuclei reduces to $12.5\%$, the mean life of the nuclei is